Topic: How reliable is a 550/650 hybrid?

[Elniniomuchachos]

I've seen quite a few people on this forum building up 550/650 hybrid engines. Not too long ago I had my 550 engine breakdown on me and have been weighing my options. As of now I'm pretty sure I'm going to do the 550/650 hybrid build, but just have one important question. Exactly how reliable are these engines compared to a stock 550? I have a few road trips I would like to do this upcoming summer. I know the 550 stock is plenty powerful to do them, but mine just crapped out on me and I would like a little more power. Will the reliability stay the same or is there a greater chance for breakdowns and or boom factors ?

The route I'm thinking of going is just taking a 650 crank and top end and throwing it on 550 cases (With all of the machine work done of course).

Tell me what your guys' experience with them are and what you think.

Also, any gas mileage reports yet?


-Elninio

[trueblue]

I don't know about what you're proposing, but the stock 650 motor is as reliable as they come.  I have done about 5000 miles on mine and haven't layed a spanner on it, other than servicing, since I got the bugs worked out, it had sat since '84.  Best of all, no points to adjust .

[scunny]

as said above, no reason for it not to be reliable. you will like the extra liveliness that the 650 head provides.

[rb550four]

I have an 80 650 with over 30k, never been worked on other than routine service, and has way more power than any of the 550's in my garage, I've been pleased with it. I also was thinking of a 650 in a 550 for some time, and decided to just do it a few months ago when an 81 650 became available to me.
   I make it a habit to purchase entire bikes instead of just motors but ,there's a catch, the 81'650 is so highly advanced compared to the 550 that you may find yourself using front and rear suspention  along with the comstock wheels because of the dual front brakes....then the electric...and pretty soon there is very little 550 left. But had I only  picked up just the motor most of the 550 would be 550. Just so you know, the upgrades on the 650 make it really,really hard to pass up when it comes to transplanting parts.

[Elniniomuchachos]

I have an 80 650 with over 30k, never been worked on other than routine service, and has way more power than any of the 550's in my garage, I've been pleased with it. I also was thinking of a 650 in a 550 for some time, and decided to just do it a few months ago when an 81 650 became available to me.
   I make it a habit to purchase entire bikes instead of just motors but ,there's a catch, the 81'650 is so highly advanced compared to the 550 that you may find yourself using front and rear suspention  along with the comstock wheels because of the dual front brakes....then the electric...and pretty soon there is very little 550 left. But had I only  picked up just the motor most of the 550 would be 550. Just so you know, the upgrades on the 650 make it really,really hard to pass up when it comes to transplanting parts.

Good info, at this point I really just need a 650 engine or crank and up in parts. I already have a dual disc setup on my 550 and I'm not a fan of the comstar wheels. I've had a few leads come to me about some 650 engine parts so hopefully I'll get a deal . I'm really looking forward to this engine build for the experience and most importantly to feel the power difference.
I've ridden a 650 before but the owner takes poor care of it and it would barely top out at 70 mph. But it did have more lower end grunt compared to my 550. He's one of those guys that bought a "cafe racer" and uses it "everyday", but knows nothing about the bikes, how to work on them, or what carburetor is.

[crazypj]

No idea what your intending but I did a lot of work on my 550 (591cc, half race cam, exhaust, ported, etc) then did 70,000+ miles on it.It's in avatar at 100,000 (really about 106,000, had a few speedo cables break)

[Elniniomuchachos]

No idea what your intending but I did a lot of work on my 550 (591cc, half race cam, exhaust, ported, etc) then did 70,000+ miles on it.It's in avatar at 100,000 (really about 106,000, had a few speedo cables break)

Ha that's awesome. Guess I shouldn't be questioning the reliability of these engines. I've just had some bad luck with my 550's lately. Just curious, how many of those miles were long trips? I'm planning on doing some long travels this summer probably around 5-6k if not more in one setting.

[Elniniomuchachos]

What I have planned is just to take the 650 crank and everything above it and throw it into the 550 cases for now. Eventually I want to work up to something like paulages big bore build. But I think I should start with a basic setup and work from there.

[dave500]

would it be easier and cheaper to put a complete 650 motor in?no expensive machine work?

[Elniniomuchachos]

would it be easier and cheaper to put a complete 650 motor in?no expensive machine work?

Perhaps it would be, but I kind of just want to build it to build it you know? Plus I want to have kickstart as my wiring isn't setup for electric start. Also there's money burning a hole in my pocket...

From what I understand the only real machine work that is needed is to move the cam chain tensioner slots forward and then some with the crank to accept the stator and ignition. Correct me if I'm wrong, it's been along day... house/yard work, garage cleanup and I just wrangled my 550 engine out of the frame by myself and put in the 500 to keep me goin'.

[crazypj]

What I have planned is just to take the 650 crank and everything above it and throw it into the 550 cases for now. Eventually I want to work up to something like paulages big bore build. But I think I should start with a basic setup and work from there.

 Usually less than 500 miles (I was living in Britain)
Longest trip was 2,000+ miles down to Bol 'Dor in south of France with a bit of chasing around thrown in for good measure (including chasing a Swiss CB900f down the French alps at '27mph officer')

[sinister902]

I've been wondering this as well, paulages should hopefully chime in....I've been gathering parts for the better part of a year now thanks to his thread and information from other members chiming in....I'm going big-bore though....I've gotten a complete 650 motor for $250, cb750 cylinders for $40, 836 kit for $110, and GSXR1000 rods for $75.....and happen to have a popped cb550 motor to use for cases so I can retain kickstart.....just have to track down cb650 wiring harness and associated electrical parts and I can get on with the build.

[onepieceatatime]

.....just have to track down cb650 wiring harness and associated electrical parts and I can get on with the build.

I have 3 or 4 wiring harnesses, not counting the ones in use on my bikes... PM with an offer if you are interested.

[Elniniomuchachos]

I've been wondering this as well, paulages should hopefully chime in....I've been gathering parts for the better part of a year now thanks to his thread and information from other members chiming in....I'm going big-bore though....I've gotten a complete 650 motor for $250, cb750 cylinders for $40, 836 kit for $110, and GSXR1000 rods for $75.....and happen to have a popped cb550 motor to use for cases so I can retain kickstart.....just have to track down cb650 wiring harness and associated electrical parts and I can get on with the build.

Haha sweet, I'm going this route as well. I came across an 836cc kit on ebay and snagged it, a Christmas gift to myself  . I'm still gathering parts but I'm getting pretty excited. I have a 550 engine with about 9500 miles on it that gave out on me a while back, so that will probably be my base for this build. What carbs are you planning on using?

[sinister902]

Haha sweet, I'm going this route as well. I came across an 836cc kit on ebay and snagged it, a Christmas gift to myself  . I'm still gathering parts but I'm getting pretty excited. I have a 550 engine with about 9500 miles on it that gave out on me a while back, so that will probably be my base for this build. What carbs are you planning on using?

I've got a set of early cb750 carbs that I'm probably going to use....if not I'm also considering using GSXR or CBR throttle bodies and running fuel injection on microsquirt.....not sure I wanna get that crazy yet....although I WOULD love to break 100hp on it....


onepieceatatime.....I'll PM you, I didn't see your post until just now.